The West Avenue Neighborhood Improvement project impacts 178 properties, which result in 192 areas that require harmonization. Thus far, out of the 192 areas, the project team has developed harmonization plans for 192 locations. The team has presented 24 properties with proposed plans and received their feedback. The team will continue to meet with properties, presenting fully detailed harmonization plans prior to commencing construction on the harmonization work.
Two overarching concerns have been identified: 1) community members have expressed a concern over the potential costs which could be incurred by private properties to restore or rebuild private improvements affected by the project; and 2) certain property owners are requesting the City’s approval to allow private property connections to the City’s stormwater system.
Private Property Harmonization
The elevation of roadways requires that the newly constructed roads, being at a higher elevation, be reconciled with the adjacent properties’ elevations – a process known colloquially as harmonization. While the harmonization efforts endeavor to satisfy the requirements of private property owners, there are certain, special or atypical, features within the City’s right-of-way. These features often have established variance agreements that explicitly require the private property owner to pay for their removal and replacement. Features without these agreements are right-of-way encroachments, not approved by the City. Additionally, since the features are unique and a standard removal and replacement process cannot be developed, the costs associated with the removal and replacement of these features were not contemplated as part of the scope of the DCP.
The DCP directs the Design-Builder to replace driveways and walkways with matching asphalt or concrete. In cases where existing driveways have been constructed using different materials (pavers, tiles, stamped concrete, etc.), the Design-Builder is currently directed to replace those materials with concrete or coordinate with the property owner to determine if the existing material can be salvaged and re-used at the owner’s expense.
There are several other features which may be impacted by harmonization including, but not limited to, fences, walls, gates, railings, and landscaping. The DCP requires the removal, re-installation, or modification, of these components to be done at the owner’s expense.
While staff continues to work with private property owners to address their concerns, the policy should reflect that costs associated with the removal and replacement of these atypical features, whether on the City’s right-of-way or within a harmonized area of the private property, is the responsibility of private property owners.
Residential/Commercial Property Run-off and Public Drainage Infrastructure
In addition to the challenges posed by the required harmonization, certain properties will need to address drainage requirements.
The City of Miami Beach operates a citywide stormwater management system that collects, conveys, treats, and disposes of stormwater runoff from public rights of way. The primary function of this system is to facilitate travel along thoroughfares while maintaining a safe and livable condition for the City’s residents and visitors. Recently, the City has undertaken a significant capital program that upgrades the stormwater system to account for sea level rise and climate change.
During the development of its capital program, the City consulted numerous subject matter experts (including the Urban Land Institute) and developed a holistic stormwater management strategy - one that attenuates flooding while mimicking nature’s water cycle. In addition, the team and community members received validation of the project’s goals and valuable feedback from the West Avenue Resilience Accelerator, a partnership between 100 Resilient Cities and Columbia University. The current strategy provides a framework for a sustainable approach to urban stormwater management. It includes the elevation of certain roadways, to minimize sunny day flooding, and incorporates green infrastructure that replenishes the freshwater lens and mitigates the transport of excessive nutrient loads into Biscayne Bay.
Therefore, to ensure that stakeholder concerns are properly addressed when implementing this strategy, staff has developed the following policy. The policy endeavors to address private property concerns, while aligning with the overall stormwater management strategy. The policy would apply to any private property (residential or commercial) that satisfies the stipulated conditions and is enumerated below.
Design Storm Event - a 10 year/24 hour storm as defined within Resolution No. 2017-30039.
Habitable Space – the building livable area, as defined in the Miami-Dade County Property Appraiser’s Glossary of Terms. The livable area represents the space used for habitation purposes. Typically, livable area will have access to electricity, plumbing and oftentimes air conditioning. It may include hallways, closets, bathrooms, storage and other areas outside the main living structure. It does not include garages, carports, and patios.
Predevelopment Model – a model of the existing stormwater drainage system, representing its performance during the design storm event.
Post Development Model - a model of the proposed stormwater drainage system, representing its performance during the design storm event.
Public drainage improvements will not subject private properties to additional flooding. Consequently, the finished floor elevations of habitable spaces will not have an increased risk of flooding during the design storm event. This will be demonstrated by comparing a predevelopment and post development model.
In order to maximize water quality treatment, private properties should retain the first 1-½ inches of rainfall on their premises.
Properties must accommodate the percolation of all staged water within a 24 hour period.
In cases where the finished floor elevation of habitable spaces within private properties is located below the future crown of the adjacent roadway and the private property owner’s consent is obtained, drainage will be provided within the private property and connected to the City’s stormwater system. The private property drainage system, when possible, will be placed at an elevation to retain the first 1-½ inches of rainfall on the premises and public infrastructure will be sized to address water quantity.
When the retention of the first 1-½ inches of rainfall will flood habitable spaces, the private property drainage system will be placed at an elevation below the elevation of the finished floor of habitable spaces and public infrastructure will be designed to accommodate water quantity from the private property. Water quality treatment will remain the responsibility of the private property owner and the private property drainage system will be placed at an elevation that maximizes the percolation of staged water.
In cases where the finished floor elevation of habitable spaces is located above the future crown of the adjacent roadway and the grade elevation of the private property is substantially low, thereby not allowing water to percolate on site, drainage may be provided within the private property and connected to the City’ stormwater system at the discretion of the City Engineer. The private property drainage should be designed to maximize the water retained on site and public infrastructure will be sized to accommodate water quantity. Water quality treatment will remain the responsibility of the private property owner.
The intent of this policy is to provide a functional direct drainage connection to private property owners. Any restoration work on private property associated with the construction of the drainage connections will be limited to the materials defined in the DCP for harmonization work. As such no specialty materials or features will be restored by the City, and the costs of restoring the private property beyond utilizing concrete, asphalt, or sod will remain the sole responsibility of the private property owner.
All water quality treatment requirements, stipulated by DERM or any entity with jurisdiction, will remain the sole responsibility of the private property owner. These include, but are not limited to, the retention of the first 1-½ inches of rainfall, the sequestering of contaminants, and the sequestering of nutrients.
Any direct private property connections to the City’s stormwater system are intended as a temporary condition. The direct connections will be removed, and no new direct connections will be allowed, once the private properties are redeveloped.
In order to proceed with the West Avenue Neighborhood Improvement Project that addresses critical needs within the water, wastewater and stormwater systems, the project team requires direction regarding drainage and harmonization policies.
The project team is proposing a formal City policy that remains consistent with the harmonization requirements of the DCP. The policy provides relief to private property owners that cannot manage stormwater runoff onsite, while aligning the project’s harmonization with the City’s holistic stormwater management strategy
Results from the 2019 Resident Survey show that 50% of residents rated efforts to manage stormwater drainage and flooding as excellent or good. In order to continue maintaining excellent standards in this area, the City recommends approving the West Avenue drainage and harmonization policy.